METHOD FOR EXTRACTING LITHIUM FROM SALT LAKE BRINE AND PREPARING ALUMINUM HYDROXIDE SIMULTANEOUSLY

摘要

The present invention relates to a method for extracting lithium from salt lake brine and preparing aluminum hydroxide simultaneously. The method comprises: a. adding aluminum salt to the brine to obtain a mixed salt solution A, adding an alkali liquor to the mixed salt solution A for a coprecipitation reaction, then performing a crystallization reaction, solid-liquid separating after the reaction is ended, and obtaining a magnesium aluminum hydrotalcite solid product and lithium-containing brine; in step a, the alkali liquor being a carbonate-free alkali liquor; b. evaporating and concentrating the lithium-containing brine to obtain lithium-rich brine, adding the aluminum salt to the lithium-rich brine to obtain a mixed salt solution B, then dropping the alkali liquor to the mixed salt solution B for a coprecipitation reaction, solid-liquid separating after the reaction is ended, and obtaining lithium-containing liquid and a lithium-containing layered material filter cake; in step b, the alkali liquor being a carbonate-free alkali liquor; c. dispersing the lithium-containing layered material filter cake in deionized water to formulate suspension slurry, and after adjusting the pH value of the suspension slurry, enabling the suspension slurry to undergo a delithiation reaction; d. filtering the slurry obtained after the delithiation reaction, and obtaining a lithium-containing solution and an aluminum hydroxide filter cake; and e, washing the aluminum hydroxide filter cake by the deionized water and then drying same so as to obtain an aluminum hydroxide solid.